The Godless Boys by Naomi Wood

Imagine an alternative England, where the Church controls the country and non-believers have been exiled to a remote island. On the Island, a fierce group of boys patrols the community, searching for signs of faith and punishing any believers. When a new girl appears, arriving from the mainland to search for her long-lost mother, the gang is split: one boy falls in love with her, another seeks violent revenge. The struggle between them will change everything.

An Officer and a Spy by Robert Harris

Paris, 1895: an army officer, Georges Picquart, watches a convicted spy, Alfred Dreyfus, being publicly humiliated in front of a baying crowd. Dreyfus is exiled for life to Devil's Island; Picquart is promoted to run the intelligence unit that tracked him down. But when Picquart discovers that secrets are still being handed over to the Germans, he is drawn into a dangerous labyrinth of deceit and corruption that threatens not just his honour but his life...